Method of and apparatus for producing continuous sheet glass



Parenteel @ce 2, in L.

' creata i- Td JOSEPH CROWLEY, OF TOLEDO, OHO, ASSIGNOR TO THE LIBBEYOWENS SHEET GLASS COMPANY, OF TOLEDO, OHIO, A CORPORATION OF' OHO.

METHOD O3? AND APPARATUS SFOR, 'PBODUCING CONTINUOUS SHEET GLASS.

Application led June 20,

T o aZZ whom t may concern:

Be it known that l, JOSEPH P. CROWLEY, a citizen of the United States, residing at Toledo, in the county of Lucas and State of Chio, have invented new and useful 1mprovements in Methods of and Ap iaratus for Producing Continuous Sheet Glass, of which the following is a specification.

This invention rela-tes to a new process and i@ apparatus for producing continuous sheet glass, and is, more particularly, an improvement in the art of flowing molten glass into sheet' form.

The failure of previous attempts to flovv Le glass downwardly through a slotted former, have been largely lue to the teiulency of the hot ,glass to adhere to the walls of the container, and the sides of the slot. and as this g ass cools it forms so-called dogrrnetah which obstructs the opening and causes linesand other defects in the sheet.

In thc presant invention, the above difficulty is largely obviated. by forming the slotted hopper or receptacle, through which the molten glass flows into sheet formi` of graphite-clay or a similar composition, to which the hot glass will not adhere, but over which it freely slides without injury to the sur-faces of the molten ,glass as it takes sheet 53@ forni.

A'further object of the invention is' to provide a device for directing the down- Wardly moving sheet into a horizontal plane, Afor convenience in tlatteningand further 95 handling. This device is also formed of a heated slab of graphite-clay which has an upper concave surface over which the hanging are of the sheet may slide Without being` scratched or otherwise injured. e0 The invention will be more clearly understood from the following;r detailed ldescription of an apparatus Well adapted to carry out the principles of the invention.

In the accompanyingr drawings: 5 Fig. 1 is a longitudinal vertical section through the maia portions of the apparatus. l Fig. 2 is a perspective of the former or hopper.

At i is indicated thel endof the refining .tank of acontinuous tank furnace, the molency for the glass to stick and accumulate i921. serial no. 479,739.

ten glass 2 flowing out therefrom at 3, into the stationary hopper or former 4. This hopper, which is of the general form shownin Fig. 2, comprises an upper supporting ledge @extending around three sidesat the upper edge, the fourth side being; open at (i to form an inlet for the Howing molten glass. The sides of the hopper converge down- Wardly till the space therein terminates in a long narrow slot 7 through the bottom. The lower edge of the hopper is rabbeted at 8 to form a second supporting ledge for the container or hopper.

This hopper is preferably made from a composition known as lgraphite-Clav, being, as the name implies, a mixture of clay and graphite. The smoothness and lubricating. qualities of this material is contributed by the graphite, the clay being combined in` sufficient quantities to givev the requisite strength to the composition. T his material has great heat-resisting qualities, and, when highly heated, the graphite ycontent will rather on the surfaces, forming' a smooth, non-scratching surface to which molten glass does not adhere. Also, the glass, even when partly cooled and set into sheet form, will slide freely over this graphite surface with out injury. Consequently, there is no tendat the outlet slot 7.

The hopper or former is housed-over at 9, and is supported by the side Walls 10 and .11, on which rest the ledge l5 and inlet 6, respectively. The lower edges of the hopper also rest upon theA bottom Walls 12, which project into the rabbets 8, already described. Suitable burners such as 13, 14:, 15 and 16 supply heat to the enclosing spaces between the outer walls and the hopper, to maintain the hopper and the molten glass therein at the requisite temperature. The housing 9 above the hopper is heated from the furnace itself, also by the burners 16. Further burners may be used above the glass, in housing`9, if found necessary.

The supportinpr structure 17, below the mechanism justy described, is open at the ozono.

Snro ii is ueuoiiy more convoiiioot io hair die the formed shoot in e. horizorim plane7 meehonism is here disclosed for doiiocting the ownwerdy iowino; sheet into o. horimmol piane. 'The soii plastic she-:eo 2O is hooi', through o maturo?! are ois ai; 2l, ood drown o' iarough o suitable drawing' azi a-eningr mechanism 29 which may bo of the romeni form now used in the welbknowo olbum' process of drawing sheet gioss, as exampe, in tho 'patent to W. Colburn, 1,248,809, granted Bec. 4f, 1917.

To support the sheer, while 4passing liirough the oro 2i, rv Slob of graphite-day or simiior materio 22 (preferably he same he hopper 4i), homing e concave upper surface as at 23, is omployed. The space housed beneothrhis slab 22, is hezred by burners 'such as .2i emi 25, so that the deiecing slab 22 Wiii bo moinzeinod ai; such o. empemsuro itfhoi vthe shoe?, 20 resizing and' sdmg inhereupom will riot be cracked or sudden temperature eheiiges. l found necessary, mild burners moy be voed obovo rile sheet, as et 26 and 2?,

' gies@ Wii from rile o'moinmin the sheet 20 et the proper bemperoouros beforo vifs-passeer odi over the sup porting roils, into eniiig' mechanism 29.

i ho sheet mormoiiy will bend through rino orc 2. Withoutony sopporin mean@ being necessary bui; rho 'She-o5; moy or, .amy time resi; iighoy upon and slido upon 'the smoo'oh graphit@ surfe/oe o hea-rod slab 22, Without 'boing ooroooiied or injured thereby.

he oporoion of this epp-aretus is simpie,

ho drawing and. Hoof ond sriooi boob/ious. from the preceding desompion. When the sempemture of the orririg glossv #sind the speed of the drawing mechanism 2Q, oro properly coordinare@s the comiouously ow in sheet form hopper on and aler beingr deiected iayiiue Slab 22 imo the horizontal plane, be drown or oiirough drawing and aening mechanism A29 sind pass to the leer anni cutzing mechanism@9 not shown.

lo' is' ibo be understood hat the @erm White-dey as here used, sind ,as used in e following cioims, covers my' suitable ioriary graphite-dey hoppa-sr liiirougii which the molten glass ioWs to give i4; form.

in a. sheoo glass producing apparatus, e graphite-doy hopper having e. tapered Slot, ohrouggh which "who molten gloss Hows.

6. In. o shoe; gloos producing apparatus9 e source of molten gioea, a. grop'iiao-ciay hop por into which Itho gloos ows from tho source, there being o siot in tiro bottom of the ho. por through which Itho ginas ows .in shoot form.

7. In a. sheet gloss producing opporoifno, o. source of mollen gloss, e groohioeiey iiog.im per into which 'he giogo 'iows from obo source, there beiiig si, so'; in the 'bottom of the hopper hrough which iie gime io'o's im sheet form, and moons :for heating loe ifiopj por.

8. In o eheeb giogo source of molen gloss, a. graphiocioy hopper imo which he gess ows from tho source, hero being; o slot in tho kortom of he hopper through which the gloss flows in shoot form, moons for heating the hopper, and heaters et the sides emor es from the hopper.

9. .Ln o. shoot glass producing apparatus@J source of molen glass, o grapi^fi1ec1ay hoppor' into which the glass flows from the source, there being o sioi; in ho bottom of the hopper through which the glass Hows in sheet form, and a. curvod grephitoeley slab below the hopper for deocing the Sheer, into a horizonto plone.

10. "in o sheet glass producing apperooos, o. source or moloon gioie7 a grophio-coy hopper into which the source, there being a slot in @he kortom or the hopper through which the gloss @mrs in sheet form, and graphtoclay slab o q 'w the hopper, having o concave oufer'oure. for defecting the plano.

11. In a sheet gloss a source of moioen goss, a, graphite-clay hopper into which the glass Hows from the source, he hopper through 'which the loroeiuciog opporaus,

glass r'ows .from Mie o sheet into o, horizonfoiv u there being a. sot in the bottom glass {iov/a of the sheet; oe it roducng eppareouo, 

